Warning! Spoilers for Teenage Mutant Ninja Turtles: The Last Ronin #1 below.

In Teenage Mutant Ninja: The Last Ronin, Michelangelo is the last remaining Turtle alive, as his brothers have fallen in their fight against the Foot Clan. However, a new preview for the third issue of the dark series teases the deadliest mission for the Turtles in a flashback that could show how Donatello and Leonardo's story ends.

The Last Ronin has both returned the Turtles to their violent, Daredevil-inspired roots, while also being one darkest stories ever told in the iconic franchise. The comic is chalked-full of action and emotion, as TMNT co-creators Kevin Eastman and Peter Laird have returned to craft something truly special. In the bleak future, Michelangelo is alone as his family has been killed by the Foot Clan. He's mastered martial arts and despite being suicidal, has made it his last mission to take down the Clan's new leader. Readers have already seen how Raphael went out in a blaze of glory, but new art teases a potentially deadly mission in a flashback.

Related: TMNT: The Last Ronin Originally Had Raphael Nearly Kill Splinter

Teenage Mutant Ninja Turtles: The Last Ronin co-writer Tom Waltz showcased a new image for the upcoming third issue, which shows Donatello doing what he does best: machines! In the art, Donatello is inside a ship besides Honeycutt as they prepare for an upcoming mission alongside Leonardo and Michelangelo, who are with Splinter. While this might seem like a fairly average setup scene, knowing that the Turtles are killed and Honeycutt gets his head chopped off, it's a real possibility this is a flashback to how the group finally splintered.

The hashtag #FightorFlight has been used to tease the issue, as a picture of April O'Neil was also released by Waltz - calling her a survivor. We know from previous issues that O'Neil lost multiple limbs but made it to the dark future alive - perhaps, readers will see how she became injured.

The cover for issue three has already teased the death of Casey Jones as well. With all these hints, it certainly appears the Teenage Mutant Ninja Turtles (sans Raphael) will embark on the journey that left the group permanently scarred. Donatello and Leonardo are both dead in the Last Ronin's dark future, and with just three issues remaining, readers will be filled in on how that happens sooner than later. It's very likely Teenage Mutant Ninja Turtles: The Last Ronin will feature their deadliest mission and show how the Turtles (and possibly more characters) fell in battle. TMNT fans should buckle up because #FightorFlight is going to be a big issue.

Next: Planning for TMNT The Last Ronin Started Over 30 Years Ago